1. Field of the Invention
This invention relates to a novel antimicrobial inorganic composition and articles coated with the inorganic composition,and an organic antimicrobial composition, and a process of making such articles. More specifically, it relates to a composition comprising low temperature far infrared irradiating metals supported on a porous honeycomb shaped substrate, and an organic quaternary ammonium salt bonded on a porous honeycomb-shaped substrate.
2. Prior Art
Antimicrobial metals have been known to be incorporated into paints and fibers for industrial or home applications. Organic quaternary ammonium silane has been shown to have anti-algae properties. The following patents show the use of silver, copper, and zinc in antimicrobial substances, and the use of organosilicon compounds.
U.S. Pat. No. 3,865,728 discloses an organosilicon compound coated on a fibrous substrate and then heated to 65-100 degrees C. The resulting product is used for control of algae in aquarium tanks.
U.S. Pat. No. 5,147,686 discloses an antimicrobial powder made by coating a titanium oxide substrate with antimicrobial metals including copper, zinc or alloys of Cu-Zn, Cu-Ag, Cu-Al, Cu-Sn or the combination of these metals. The composition is useful against various microorganisms such as E. Coli, Salmonella typhimurium, and others. The coated substrate is fired at 400 degrees C. The powder form of this product is intended to be incorporated into a resin.
U.S. Pat. No. 5,151,122 relates to an antibacterial ceramic material. Various ceramics such as zeolite or alumina or clay are described as being fired at temperatures as high as 1200-1300 degrees C. so as to lock in the absorbed antibacterial metals such as silver, copper, or zinc. The patent further suggests that the product can be added to a resin which can be molded into any shape.
U.S. Pat. No. 5,415,775 relates to an ultrafiltration membrane consisting of alumina and titanium dioxide which has been sintered at 1000-1500 degrees C. and then coated with metal oxide. The membrane exhibits anti-bacterial properties.
U.S. Pat. Nos. 5,618,762, 5503,840, and 5,595,750 variously show Ag, Cu, Zn. Pt, Cd, Cr as antibacterial components including protective coatings.
None of the above patents shows an antimicrobial composition as disclosed herein. Furthermore, none of the above patents addresses the problem of keeping streams, water reservoirs, public baths, and fish farms clear of harmful micro-organisms including algae or bacteria. In addition to their antimicrobial properties, the articles of the present invention show high efficacy due to the honeycomb structure of the substrate which provides multitude of antimicrobial sites per unit volume and prolonged antimicrobial efficacy in flowing air or water due to strong adhesion of the antimicrobial component on the substrate, without any adverse environmental effects such as are encountered when chemical pesticides, bactericides or herbicides are used.
The object of this invention is to provide antimicrobial articles having coated thereon a novel metal composition or an organic quaternary ammonium salt according to a specific process to eliminate harmful microbes such as E. coli, Salmonella typhimurium, and Saccharomycetes such as Saccharomyces cerevisiae, Candida albicans; Algae groups,such as Blue Green Algae, Brown Algae, and Green Algae, and Bacteria such as Chaetomium globosum, Penicillium funiculosum including Legionella pneumophila. Another object is to provide inexpensive articles having the shape of porous honeycombs treated with the antimicrobial substances of this invention. Such articles can be placed in nets or cages in streams, rivers or stationary bodies of water to eliminate harmful microbes. Still another object is to provide methods to prolong the life of such articles, thereby increasing and prolonging antimicrobial effectiveness. These objects of the invention will become apparent from the following description.
The articles of this invention are porous honeycomb-shaped substrates having coated theron inorganic or organic antimicrobial components. The inorganic component is selected from the Low Temperature Irradiating Far Infrared Material, herein referred to as metal composition. Said metal composition comprises metals capable of emitting far infrared radiation having a wavelength of from 3 to 30 microns below 60xc2x0 C., which eliminates microbes. The metal composition has the general formula: AB2O4 of a regular spinel structure. It is to be noted that A and B are not chemical symbols. A is magnesium, divalent iron, nickel, manganese, cobalt or zinc. B is aluminum, trivalent iron, trivalent manganese, or trivalent chromium. O is oxygen. The composition may contain one or more of the following compounds: ferric oxide, ferric sulfide, zinc oxide, calcium oxide, titanium oxide, cupric oxide, aluminum oxide, aluminum sulfide, strontium oxide, and tantalum oxide as impurities.
The organic antimicrobial component is a quaternary ammonium salt having the formula: 
wherein m+n is 16 to 19, m is to 6, and n is 13 to 17; or m+n is 20 to 23, m is 4 to 11 and n is 9 to 17, X is halogen; and Y is a hydrolyzable radical or hydroxy group.
The porous substrate of the antimicrobial article in accordance with this invention is sodium silicate, or diatomaceous earth or a ceramic material or siliceous clay or material comparable to silicon dioxide or aluminum oxide, which has been made into a honeycomb structure either by molding or extruding. The substrate is impregnated with either one of the above antimicrobial substances and calcined at a predetermined temperature.